Timothy Revell in New Scientist:
The method to fairly split a cake between two people is tried, tested, and mathematically proven. One person gets to cut the cake and the other gets to choose which slice they get. To get the biggest piece of cake, the cutter must split it fairly resulting in no hard feeling between the two eaters.
In American politics, however, cutting states into electoral districts doesn’t have a similarly fair method. The political party in charge often decides where the electoral lines are drawn and does so in such a way to gain an advantage – a process called gerrymandering.
But now, Ariel Procaccia, Wesley Pegden, and Dingli Yu at Carnegie Mellon University have come up with a way to extend the cake cutting technique to electoral redistricting to make the system a lot fairer.
“What we think is exciting about this is that it leverages the competition of the two parties. They can both act in their own self-interest and still result in an outcome that is mathematically fair,” says Procaccia.